During a telematch, each group of pupils was supposed to collect as many coloured balls as possible. Each colour represented a certain point as tabulated:

Colours	Points
Black	4
Pink	6
Purple	9

In each container, the number of black balls was 40% more than the number of purple balls and 90% less than the number of pink balls. Given that the total possible points if the group managed to collect all the balls were 4437 points, how many balls were not black in colour?

Black	Pink	Purple
7x1		5x1
1x7	10x7
7 u	70 u	5 u

	Black	Pink	Purple	Total
Number	7 u	70 u	5u
Value	4	6	9
Total value	28 u	420 u	45 u	493 u

100% + 40% = 140%
140% = ¹⁴⁰₁₀₀ =⁷₅

100% - 90% = 10%
10% = ¹⁰₁₀₀ = ¹₁₀

Total number of points collected
= 28 u + 420 u + 45 u
= 493 u

493 u = 4437

1 u = 4437 ÷ 493 = 9

Number of balls not black in colour
= 70 u + 5 u
= 75 u
= 75 x 9
= 675

Answer: 675